A Universal STT State Assignment Method for Pulse Input Asynchronous Sequential Circuits

Methods to realize race-free asynchronous sequential circuits by using appropriate single transition time (STT) state assignments have been described in the literature. This paper deals with that restricted class of asynchronous circuits (called pulse-input asynchronous circuits) for which in every input sequence each input state liis always followed by a special input state lo≠li. A method is presented to realize any pulse-input asynchronous sequential circuit with p internal states by a universal race-free STT state assignment in 2Eovariables, where Eo=[log2n] and n≤p is the number of the elements in a defined subset of internal states.